An array called nums has already been created for you with the values {10, 20, 10, 30, 20}.

Your task is to print only the unique values: the first time each number appears. If a number has already appeared earlier in the array, skip it.

For each element, you need to check whether it appeared at any earlier index. If it did, don't print it. If it didn't, print it.

In this array:
- 10 at index 0: first time → print
- 20 at index 1: first time → print
- 10 at index 2: already appeared at index 0 → skip
- 30 at index 3: first time → print
- 20 at index 4: already appeared at index 1 → skip

Print the unique values on one line separated by spaces.

Expected output:
10 20 30